This invention relates to a boom point, and particularly to a light-weight boom point constructed as a truss framework.
Boom points mount the sheaves or other cable carriers at the working end of a boom. Although booms have been constructed in a variety of manners, such as fabricated box beams and lattice trusses, boom points have been traditionally built up from plates into heavy box like structures. This is particularly so when the boom point is likely to experience significant side loads, such as in the boom used on a dragline.
The boom point constructions used to date contribute significantly to the weight of the boom structure. This added weight detracts from the payload that the boom can hoist and handle. Furthermore, the complex fabricated plate structures are difficult to assemble and inspect. Stress fractures may develop within the structure that are not apparent by inspection.
The present invention is directed to a boom point construction that eliminates a significant amount of the weight of prior constructions and this is accomplished by eliminating primary bending forces on the structural elements of the boom point.